Hypersensitivity of sexual stimulation is known to be caused generally due to a disorder in the complex cooperation between the peripheral nervous system and the central nervous system. Hypersensitivity of sexual stimulation is known to lead in frequent cases to the onset of ejaculation before or shortly after vaginal penetration, or an inability to keep erection or control ejaculation for a sufficient amount of time for a partner's sexual pleasure.
According to recent statistics in Korea, approximately 30–50% of adult males suffer from these sexual dysfunctions resulting from hypersensitivity of sexual stimulation, which leads to domestic discord in relationships and loss of self-confidence.
Generally, hypersensitivity of sexual stimulation is caused by a malfunction of the central nervous system due to chronic fatigue of the neurotransmitter system, hypersensitivity of the urinary duct or the glans receptor, endocrinal disorders, psychological causes, and the like. However, it was recently deduced that since the above-mentioned causes may react on the nerve system in simultaneous and complex manner, or a cooperation system between the central sexual nerve system in a man may be disrupted, a reflective ejaculation can easily be caused.
Hypersensitivity of sexual stimulation has been treated by psychotherapy and drug therapy. The psychotherapy involves long-term sexual behavioral counseling therapy provided by a specialized therapist to both the patient and his partner. However, such long-term treatment programs are complicated, expensive, can be uncomfortable for the patient and/or his partner, and have a poor success rate of less than 50%.
Drug therapy has been used more widely than psychotherapy because of the prompt therapeutic effect. Available drugs include psychotropic agents which suppress excitation of the sexual nerve system, such as antidepressants, and topical anesthetic agents which desensitizes the sexual peripheral nerve to delay ejaculation. However, the central nerve depressants likely make it impossible to have sexual relationships due to a loss of sexual desire, and the topical anesthetic agents, such as lidocaine ointment or spray, are not preferred because they should be applied just before intercourse due to their short duration. Therefore, sexual dysfunctions resulting from hypersensitivity of sexual stimulation cannot be effectively treated with drugs.
Korean Patent No. 148511 discloses a preventive and therapeutic pharmaceutical formulation for hypersensitivity of sexual stimulation, which essentially contain ginseng, dang-gui(Angelicae Gigantis Radix), yuk-jong-yong(Cistanchis Herba), cinnamon(Cinnamomi Cortex), sesin(Asiasari Radix), and sumsoo (Bufonis Venenum). The effect of this formulation on hypersensitivity of sexual stimulation has been proven through animal and clinical tests, and it is commercially available for external application.
However, since the formulation contains essential oils of herbal components, such as dang-gui, cinnamon, sesin, etc., the scent of the herbal components is so strong that it smells even after washing with soap, thereby limiting the use of the formulation. Also, the formulation is prepared from the crude extracts of essential herbal components, including dang-gui, ginseng, sumsoo, yuk-jong-yong, cinammon, sesin, etc., without purification. Accordingly, the product appears an unpleasant unique dark brown color from the extracts of herbal components and may contaminate underwear. Thus, it is difficult for a patient to conceal the application of the therapeutic formulation from his partner. Further, application of the formulation is inconvenient because it takes 30 minutes to 1 hour for the local anesthetic to take effect. Moreover, since the crude sumsoo extract is used without purification, non-pharmacological substances for hypersensitivity of sexual stimulation in the unpurified sumsoo extract, such as epinephrine and serotonin, may result in various side effects, such as penile smooth muscle contraction and impotence.
WO 0147539A1, pharmaceutical composition for preventing and treating erectile impotence using purified sumsoo extract, discloses sumsoo extraction and purification methods for preparing a pharmaceutical composition containing only Bufadienolides, excluding catecholamines, such as epinephrine, and indolalkylamines, such as serotonine. The purified sumsoo extract effectively eliminates the side effects of sumsoo extract obtained using water or alcohol as an extraction solvent in Korean Patent No. 0148511, such as impotence, penile smooth muscle contraction, and pain.
However, Bufadienolides used as the pharmaceutical component for treating hypersensitivity of sexual stimulation have both topical anesthetic and penial smooth muscle contraction effects. Therefore, side effects such as impotence cannot be suppressed only with the purified sumsoo extract alone.